Signal system



C. B CH SIGNAL SYSTEM Oiiginal Filed Nov.

I MENTOR Patented Mar. 3, 1925.

UNITED STATES g 1,528,597 PATENT. OFFICE.

CLARENCE E. BEACH, OF BINGHAMTON, NEW YORK.

SIGNAL SYSTEM.

Original application filed November 3, 1919, Serial No. 335,480. Divided and this application filed Qctober 5, 1823.

T all whom it may concern:

Be it known that I, CLARENCE E. Bnncrr, a citizen of the United States, residing at Binghamton, county of Brooms, and State oi New York, have invented certain new and useful Improvements in Signal Systems, oi which the following is a specification.

This invention relates to electrical signal systems employing a plurality of conductors, and is particularly adapted for use in systems employing such conductors in varying comb-inations,such for example, emergency signal systems provided for fire alarm, night watch and similar service, and comprising a central stationhaving suitable current supply and manifesting mechanism, a plurality of distant signal initiating stations having circuit-breaking and circuitgrounding mechanism, and a normally closed line-circuit in which such stations are connected.

In an application filed by me November 3, 1919, Serial No.*335,4l30, of which this is a division, I have shown, described and broadly claimed signaling systems embodying this invention; and have also there shown, described, and specifically claimed signaling systems similar to that of this invention except that in the use of systems such as there specifically claimed it is necessary to depend, for advantageous utilization thereof, upon the availability of a cur.- rent source delivering alternating current energy, such as-is ordinarily supplied by commercial lighting and power systems.

It is an important object of this invention to provide such a system having an arrangement of current paths and appliances which may be advantageously employed where only direct current sources are avail able such as primary or secondary batteries.

Other objects of this invention will be in part obvious and are in part specifically set forth in the following specification.

F or the purpose of facilitating the understanding of this invention, an embodiment thereof is hereinafter described in detailand is diagrammatically illustrated in the accompanying drawing. I

The current source shown comprises the three groups of cells a a and which groups are connected in series one with an.- other and may consist of either primary or secondary cells.

Serial No. 666,744.

Groups (1 and ashould preferably contain such number ot' 'cells as to aflord sub stantially the same effective voltage, which voltage should suit-ably exceed that of group (5 for reasons to be hereinafter more fully explained; while group a should contain 7 such number of cells as to provide voltage suitable for the normal current path. The terminal is connected to a terminal of the group a? which is also connected with a terminal of the group 65 and the termi nal 27 is connected to the other terminal of said group (1?.

The relays B and D each have one terminal thereof connected to the terminals 25 and 27, respectively, and the remaining terminals-of said relays are connected with the central oflice line-wire terminals '28 and 29, respectively.

The relay 0 is provided with two windings, an end of one of which windings is connected to the free terminal of battery group a and an end of the other of said windings is connectedto the free terminal of battery group a These windings are so connected that, should the remaining terminals thereof be connected together, the flow of current therethrough will cooperate to energize the magnet of said relay to the end that intended current flow through each of said windings will cause like polarity of magnetization of said magnet.

The free terminals of the respective coils on the relay 0 are connected through a pole-.

changer with the ground 68 The pole-changeris shown as comprising a magnet 92 whose. armature 93 is connected through the conductor 94 to the ground 68 the front and back stops of said armature being connected through the conductors 95' and 96 to respective windings of the. relay 0.

To obtain best results, the condensers 97 and 98 should be connected between the groundconductor 94- and the conductors and 96, respectively, so as to bridge the break gaps between the armature 93 and the.

nism is shown for convenience of illustration, but it is evident that any of many other well-known forms of automatic polechangers may be substituted for that shown and just described.

A three-pen registeris diagrammatically indicated at E, comprising the paper tape roll 30, the free end 31 of which passes under the marking ends of the pens 32, 38 and 34. Said pens are independently operable for the purpose of suitably marking upon the tape .31 in response to energization of the actuating magnets 36 and 37, respectively.

A suitable register battery 38 is shown. Oneterminal of said battery is connected to the armatures of relays B, c and D, and the other terminal of said battery is connected to one of the leads of each of the magnets 35, 36 and 37. The remaining leads of magnets and 37 are connected to the back contacts of relays B and D, respectively, and the remaining lead of magnet Stiis connected to the trout contar-tof relay (2.

It is assumed that there will be propel ling means for the paper tape 31; but as registers embodying such means are well understood by those skilled in this art, and inasmuch as the detailed construction of the. registering mechanism forms no part ot this invention, further illustration or description of same is omitted in the interests ot' clearness and brevity.

It should be understood that the batteries 88 and 99 are shown independently of one another and oi the main signal circuit current source, merely in the interests of convenience and clearness of illustration. In actual practice, the current for the operation of the register E may, if desired, be secured from the current source provided for the signaling circuit; and the energy for the pole-changer P may, if desired, be secured from all or part of the battery groups a a and a Suitable initiating stations, such as F, G. H, I and J, are shown serially connected between the central ofiice terminals 28 and 29; the station H being shown on an enlarged scale, so asto facilitate illustration of the code-wheel 39, normally closed contacts 4:0 and ll, and the normally open ground contact 42 tliereat.

The code-wheel 39 is so formed that, when at rest, the contact 40 is held in conductive relation with the contact 41, but said contacts are not raised high enough to bring the contact d1 in conductive relation with the contact 42. During the rotation of the code-wheel 89, each tooth first raises the contacts l0 and ll so as to bring them into conductive relation with the contact 42, and then allows all of said contacts to separateone from another, thus providing circuitbreakingand circuit-grounding mechanism.

Suitable means, such as a manual operating handle 43, is provided for causing the actuation of the code-wheel 39.

It should be understood that mechanism comprising corresponding instrumentalities is provided at the initiating stations F, G, I and J.

The operation oi? the embodiment of this invention illustrated by the drawing is as follows:

The pole-changer operates constantly, thus alternately charging and discharging the condensers 97 and 98 through current paths as follows :W'hen the armature 93 is inter mediate its cooperating COlitliCts,ftl'O]11 one terminal of battery a through one winding of magnet of relay 0, through conductor 95 and condenser 97, through part of conductor 94-, condenser 98 and conductor 96, through other winding of the magnetof relay and through battery a and (L to the other terminal of battery a thus charging the condensers 97 and 98 in series and causing current fiow through the windings ot the mag!- net 0 in such relative directions \but the cur rent flow through each supplements the en-er gization in'iparted to said magnet by current flow through the other hereof; when the armature 93 engages the back-stop associated therewith, the condenser 98 is shortcircuited (and therefore discharged) through a current path from one terminal of said condenser, through conductor 9 L, armature 93, backtop contact and part of conductor 96 to the other terminal of condenser 98, and the charge of condenser 97 is correspondingly increased; and, when the armature 93 rests against the front-stop associated there-- with, the condenser 9. is discharged through a current path extending from one terminal of? said condenser, through conductor 9%. armature 9? and its associated front-stop. through conductor 95 to the other terminal of said condenser, and the charge of com denser 98 is correspondingly increased. It will be noted that, because of the arrangement of the connections of the windingl's of the electromagnet ot the relay 0, all current flow incident to charging of condensers 9? and 98 will traverse said windings in such res rective directions that each of said windings will cooperate with the other in exci ing and maintaining magnetization of the magnet of said relay.

The pulsating current flow through the windings of the relay 0, incident to the charging of the condensers 97 and 98 is insutlicient to cause the magnet of said relay to effectively attract its armature.

Under normal conditions,-the ground contacts 42 of the initiating stations F, G. H, l and .T are electrically isolated from the contacts 40 and a1 associated therewith: hence the ground connections of the signal initiating stations are not effective, the relay 0 will be dcenergized, its armature will ocllt) The normal line current path just referred to, extends from one terminal or": battery group a through conductor 51, terminal 25, conductor 52, wmdmg of magnet of re lay B and conductor to central oliice terminal 2S; thence through conductor 5% to left-hand terminal of station F; thence through conductor 55 of said station (as illustrated at station H) to contact 40 thereat: thence through contact 41 and conductor 56 to the right-hand terminal of station F; thence through conductor 57 to the left-hand terminal of station G, and correspondingly through station G to the right-hand terminal thereof; thence through conductor 58 to the left-hand terminal or station H and correspondingly through said station to the righthand terminal thereof; thence through conductor 59 to the left-hand terminal oi sta tion I and correspondingly through said station to the right-hand terminal thereof; thence through conductor 60 to the left-hand terminal of station J and correspondingly through station J to the right hand terminal thereof; thence through conductor 61 to the central oilice terminal 29; thence through conductor 62, winding of relay D and con ductor 63 to terminal 27; thence through conductor 64; to the other terminal of battery group e It now the code-wheel 39 of any initiating station should beset in motion, as by the actuation of the operating handle 4E3 associated therewith,said wheel will first bring the contacts 40 and 41 into conductive relation with the ground contact 42 associated therewith, and will then permit said contactsto move away from one another; after which the contact i0 will be again moved into conductive relation with contacts 41 and &2 by the next tooth of the code-wheel 39 and this cycle of operation will berepeated such. number of times and at such intervals as to formulate the desired code signal.

Upon the establishment of a conductive relation between contact 42 and the contacts 40 and ll of any initiating station, as just described current flow will be established through relay 0 such as to cause the eiiective energization of the magnet thereof and to thereby cause the energization of register magnet 36 to actuate register pen 33. Such current flow will be pulsating in character alternately traversing one and the other of the windings of the relay 0 and comprising corresponding pulsations in opposite (urea tions in the conductors 52 and although the mean effective flow in both of said conductors will not he inateriallr changed. Such pulsating current flow will tra following divided path; assuini -g: t or convenience, that the code-wheel of station H is being operated such path will extend from the central o'a'iice ground 68 through the earth to the ground Y1 thence through conductor 79 to the middle terminal of station H thence through conductor 8 of said station to contact 4-2 thereot. From co L 4l2, of the actuated station two current paths will be provided as follows: one ath through contact 41 and conductor to the right hand terminal of said station; thence through conductor 59, stat-ion l conductor 60 station J conductor 61L terminal 29 conductor 62; relay D conductor terminal 2. and conductor 64 to the tel minal of battery group c which .is connected to hattery group a"; thence through hatter-v groups c and c through the left-hand winding of the magnet of relay (as viewed in the drawing) through conductor 96* back stop and armature 93 of pole-changer, and conductor 91 to central otlice ground 68'; and the other path through contact 4s) and conductor 55 to the left-hand terminal of station H, thence through conductor 58. station G, conductor 57 station F; conductor 54, terminal 28, conductor 53 relay B conductor 52, terminal 25 and conductor 51 to the other terminal of battery group a thence, through said battery group (in the opposite direction) and through battery group a through the right-hand winding of the magnet oi relay 0 (as shown in the drawing) through conductor through front stop and armature 93 0t. pole-changer P, and through conductor 94 to central oflice ground 68. Because the windings the magnet of relay 0 are so connected that the impulses through each of aid windings excite said magnet infthe same polarity as that excited by impulses through the other of said windin s. supplementing the residual magnetism which persists after the preceding impulses; much more effective response may be obtained from ordinary commercial types of relays than if all impulses passed through both windings and thereby made it needful for eachimpulse to overcome both in the magnet an its armature, the residual magnetism from the preceding impulse. t

It is evident that while this divided cur-- rent path is eii'ectire, as just described the energization of relays l o and D will h of substantially equal eilectiveness, so that,

lllt) during the periods when the ground connection or" any initiating station is efiective the armature of the relay 0 will be'in attracted position and the arinatures of the relays l3 and D will remain in their normal attracted positions.

Whenever the cont ct of any initiat ing station drops into a notch in the codewheel 39 cooperating tlu ewith. said contact 40 will move away our the contact -11, and the contact 421 will, at the same move away from the contact thus brea ing the ground connection and interrupting current flow through relays ll. c and l), thus permitting the armatnres of said rclays to move to retracted position. lhe retractive movement of the armatures of rclays B and D will cause energization of the register magnets and 3. and the corresponding movement of the armature of relay 0 will cause deenergization of the register magnet 36.

Continued rotation of the acting codewheel 39 will thereafter move the contact 40 associated therewith into conductive re lation with its cooperating contact 4i. thereafter move said conta 40 ant conductive relation with their contact 42. Such conductive relationship between contacts 40 and ll. will serve to re-establish current flow through the normal current path already described, thereby reencrgizing relays ll and D. which relays will thereupon act to cause decnerg sation of register magnets 35 and 3?: and such couductivc relationship between contacts 40 and 41 and contact 42 will serve to re-establish current flow through the ground path as hereinbefore described, so as to cause recnergisation of relay 0, which relay will then act to cause reenergization of register magnet 36.

From the foregoing it will be apparent that, when all curl nt paths are in prop-m: condition, the actuation of any initiating station will cause its code sig i to be recorded concurrently by pens 32, 33 and 34-, although the record produced by the pen will be somewhat advanced, in point of time. from records produced by pens 32 and 34.

$hould the signal circuit be broken, as, for example, at 80,-relays B and D will be deenergized, and register mangets and 3'? will be energized thus giving the intended warning of such a break.

If any initiating station is actuated while the normal current path is interrupted. as by a break at 80, the relay 0 and either the relay B or the relay 1), as the case may be, will be energized during each of the periods when the contacts 40 and 41 of such station are brought into conductive relation with the cooperating contact 42, and the code signal of such station will therefore be manifested by the pen 33 and by either the pen 32 or the pen 34.

During any signal, such as just described, if any initiating station located at the other side of such a break is actuatcd,'the pen 32 will manifest the signal of one of said stations and the pen 3 t will manifest the signal of the other of such stations, while the pen 33 will produce a record comprising terrupting the normal current path through i such station,it is evident that the defcctive condition of such station will he corrcspondingly manifested, and that, pei'iding the repair thereof, the signal of any st=tion connected at either side of such detective station, or of any two concurrently acting stations connected at opposite sides of such defective station, will be correctly inanifested in the manner already pointed out.

Should an accidental leakage to the ground develop, as sa gested by the dotted line 1, such leakage 1 result in current flow through the windings of the relay 0, and the energization of said relay will cause the actuation of pen to manifest such defeet. If any initiating station should be actuated du ing the continuence of such a ground leak,the signal of such station will cause responsive action of the relay B or the relay D (depending upon the position of the actuated station in the circuit with relation to such leak) and thereby cause either the pen 32 or the pen 3, as the case might be, to manifest the code signal of such initiating station.

While a station connected at one side of such a leak is acting, if a station connected in the circuit at the opposite side of such a leak is actuated, the code signals of both of such stations will be correctly manifested, one of said signals being lllfllllfGStGt hy the pen 32 and the other of said signals being manifested by the pen 34.

Should the code-wheel of any initiating station come to rest in a position which renders the ground connection thereat etlective and any other initiating station be actuated during such effectiveness or should two other initiating stations connected at opposite sides of such grounded station be concurrently actuated, the code signal or sig nals of such station or stations will be correspondingly manifested.

It is evident that should the code-wheel of any station come to rest either in a position which renders the ground connection effective or in a position which breaks the normal signal current path,the actuation of such station will nevertheless cause its code signal to be correctly manifested by the register E.

Should the line wires become crossed, so as to shunt out any one or more initiating stations, as suggested by the dotted line 82; or should the normal current path be shortcircuited, as suggested by the dotted line 83 between the central office terminals 28 and 29,no immediate warning would be given by the central oflice equipment (unless such shunt included a ground connection).

While any station or stations, or the entire normal current path is short-circuted, as just described, if any initiating station is actuated, upon each occasion when the ground connection of such station is made effective by the operation of the code-wheel thereat, the relay 0 will be energized, and'the pen 33 will therefore be caused to manifest the signal of such station. Under these circumstances the pens 32 and 34 will not respond. I

Should the ground connection be broken at any initiating station, as, for example, by the disconnection of the ground wire from the central terminal thereof,-the actuation of such station will cause the de energization of relays B and D, and hence will cause pens 32 and 34 to manifest the signal of such station.

Although no immediate warning is given of the short-circuiting of all or any part of the normal current path, and although no immediate warning is given of a break in the ground connection of any initiating station,it is evident that notification of such defects will be provided in the following manner. If a signal initiating station is actuated while the normal line current path therethrough is short-circuited, the signal of such station will be manifested exclusively by the pen 33, and the failure of the pens 32 and 34 to concurrently act will serve to indicate that the normal current path through such station is shortcircuited. When a signal is received from any station the ground connection of which is interruptod,----such signal will be manifested by pens 32 and 34, but the pen 33 will not act in response thereto; and the failure of said pen 33 to act concurrently with the pens 32 and 34 will serve to indicate that the ground connection of such station is defective.

If any two signal stations are simultaneously actuated at a time when all current paths are in normal working order,the signal of one of such stations will be manifested by the pen 32 and the signal of the other of such stations will be manifested by the pen 34; and the pen 33 will respond to all impulses of both stations; so that the signals of such stations will be manifested by the pens 32 and 34, respectively, without interference.

From the foregoing it will be evident that when the pens 32, 33 and 34 are acting concurrently,the relay B and the pen 32 will act responsively to some one initiating station, and the relay D and pen 34 will. act in response to the same or some other one tion of a short-circuited station).

initiating station but, during the concurrent actuation of two or more initiating stations, neither of said relays or pens will act in response to the impulses of'more than one of such stations. On the other hand, inasmuch as the relay 0 and pen 33 will act in response to the impulses to which both relay B and relay D are subjected when two or more signal stations are acting concurrently it is desirable that when all of the pens are acting concurrently, the code signals shall be read from the records produced by pens 32 and 34; the record of the pen 33 being considered conclusive as a manifestation of the code signal of an initiating'station only when such record is produced without concurrent records of the other pens (as would be the case during the actua- Should several or all of the initiating stations be concurrently actuated,the actuated station connected in the circuit nearest to the central ofiice terminal 28 would be responded to by relay B, during the operation of such station, to the exclusion of all other stations; and the actuated station conneoted in the circuit nearest to the central office terminal 29 would be responded to by relay D, during the operation of such station, to the exclusion of all other stations.

For example, if stations H, I and J are simultaneously actuated,-the initial movement of the code-wheel 39 of station H will establish a ground connection thereat, throughout the duration of which connection the armature of the relay B will be main tained in attracted position regardless of any circuit interruptions which may result from the actuation of stations I and J and when, after further rotation of the codewheel 39 of station H, thefirst tooth of said code-wheel iswithdrawn from the path of its contact 40,the current path through said station will be interrupted, and the relay B will be thus rendered unresponsive to circuit closures or groundings incident tothe operation of stations I and J. Succeeding teeth of the code-wheel 39 will first close the current path through station H and immediately thereafter close the ground connection through contact 42 thereat, so I that, throughout the operation of station H, relay B will be under the control of said station to the exclusion of stations I and J. o For like reasons relay D will be controlled exc usively by station J during the operation thereof. 7 In view of the foregoing it is evident that if more than two stations are actuated at or about the same time, and if such stations act to transmit their respective code signals but once, the complete code signal of one of such stations will be responded to by the relay B, so as to cause a complete and correct manifestation of such code signal by the pen 32, and the relay D would respond to the signal of some other station, so as to cause the complete and correct manifesta tion thereof by the pen 34:. Inasmuch as it is common practice in signal systems of the general type contemplated by the drawing to transmit important signals (such as, for example, lire alarms) four or more times, it is evident that even under the circumstances of concurrent action of three Or more stations. the record of pens 32 and 34 will clearly disclose and repeatedly verify the respective code signals of some two of such act rated stations. although, previous to such manitestations the signals of one or more previously actuated stations may be interrupted by subsequently actuated stations in the event hat such subsequently actuated stations are connected in the circuit nearer to the central oilice terminals than the previously actuated stations.

In the event that the signal circuit conductors are crossed at the opposite sides of one, more, or all of the initiating stations (as, for example, through the paths indicated by the dotted line 82 or 83) and, while the conductors are thus crossed, if the normal current path is broken at any point thus short-circuited (as at the point 80),-it is evident that the actuation of any initiating station connected in the portion of the signal circuit which is thus both broken and short-circuited will nevertheless be manitested through the response of relay 0 to the closures to ground incident to the operation of such station.

Should a difference in potential exist in the earth between the central ollice ground 68 and the ground of any initiating st.- tion, at a time when the normal current path is interrupted, as at the point 80, it is evident that such earth potential will not prevent the response of the relay to ground closures of any actuated iating station, as might the case it a direct current source of energy was employed in accord ance with the prior art.

lhe purpose of employi :attery groups a and a is to cause. when e ground connection of any initiating station is closed. the development of such pulsating current flows as will be substantially equal in effectiveness to the normal steady current tlow through the usual single current path.

It will be understood by those skilled in this art that under certain varieties of operating conditions and in certain varieties of circuit arrai-igement this invention may be practiced with current source arrangements in whichthe potentials of the battery groups a and (1 or their equivalents, may be substantially less than that of the group a or its equivalent and that, under other conditions and arrangements either one or both of the battery groups a and a may be dispensed with, the leads from the windings of relay 0 being then connected directly to the terminals of the battery group to or its equivalent.

In certain cases, sufhciently effective results may be obtained without employing the condensers 97 and 98, but, ordinarily, the use of these condensers will improve the operating conditions enough to warrant supplying them, by decreasing the arcing incident to the vibration of the armature 93, between its cooperating contacts and by helping to maintain the magnetization oi? the magnet of relay 0 (due to the flow ot' the charging current for the condensers 9? and 98) while said armature is traveling between one and the other of said contacts.

is many changes could be made in the construction shown by the accompanying drawing and hereinbefore described in detail, and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the foregoing description or SllOVaIl in the accompanying drawing shall be interpreted as illustrative and not ina limiting sense.

Inasmuch as my application filed Novenn her 3, 1919, Serial No. 335,430 (of which this is adivision) broadly claims signaling systems embodying this invention, it is to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described which do not fall within the scope of the claims of said copending application. together with all statements of the scope of this invention which, as a matter of language, might be said to fall therebetween.

l l' hat I claim and desire to secure by Letters Patent of the United States is:

1. In a signal system,a signal circuit; three current supply source units the electromotive force of each of two of which units suitably exceeds that of the third of said units; interconnecting media between said units, said circuit and the ground. arranged to connect the terminals of said third one of said units to the respective ends of said circuit: and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately ground one and the other of the terminals of said third of said units illlOll'Q'll respective ones of the other of said units at a frequency suitable for signaling current flow in said system.

2. Tn a signal system,-a signal circuit; a current supply source: supplemental current supply mechanism the electromoti-ve force of which suitably exceeds that of said source; interconnecting media between said source, said mechanism, said circuit and the ground, arranged to connect the terminals of said source to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force concurrently between one and the other of the ends of said circuit and the ground at a frequency suitable for signaling current flow in said system.

3. In a signal system,a signal curcuit;

three current supply source units; interconnecting media between said units, said circuit and the ground, arranged to connect the terminals of one of said units to the respective ends of said circuit; and continuously acting means for so varying the ct fectiveness of certain portions of said media as to cause said units to apply electromotive forces of similar mean effectiveness concurrently between the ground and one and the other of the ends of said circuit.

4. In a signal system,a signal circuit; a current supply source; supplemental current supply mechanism; interconnecting media between said source, said mechanism, said circuit and the ground, arranged to connect the terminals of said sourceto the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive forces of similar mean effectiveness concurrently between one and the other of the ends of said circuit, and between the ground and said circuit ends.

5. In a signal system,a signal circuit; three current supply source units; interconnecting media between said units, said circuit and the ground, arranged to connect the terminals of one of said units to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately ground one and the other of the terminals of said one of said units through respective ones of the other two of said units at a frequency suitable for signaling current flow in said system.

6. In signal system,-a signal circuit; a current supplysource; supplemental current supply mechanism; interconnecting media between said source, said mechanism, said circuit and the ground, arranged to connect the terminals of said source to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force concurrently between one and the other of the ends of said circuit and the ground at a frequency suitable for signaling current flow in said system.

7. In a. signal system,-a signal circuit; current supply mechanism; intercoimecting media between said mechanism, sat. circuit and the ground, arranged to connect terminals of said mechanism to the respect. ends of said circuit; and continue y acting means for so varying the e fectiveness of certain portions of said media as to cause said mechanism to apply electromotire force concurrently between one and the other of the ends of said circuit and the ground at a frequency suitable for signaling current flow in said system.

8. In a signal systein,a signal circuit, three current supply source units, interconnecting media bet-ween said units, said circuit and the ground, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said units to apply electromotive forces oi similar mean effectiveness concurrently between one and the other of the ends of said circuit and between the ground and said circuit ends.

9. In a signal system,-a signal circuit, a current supply source, supplemental. current supply mechanism, interconnecting media between said source, said mechanisn'i. said circuit and the ground. and continuously acting means for so varying the cf fectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive forces of similar mean effectiveness concurrently between one and the other of the ends of saic ircuit and between the ground and said circuit ends.

10. In a signal system, a signal circuit. three current supply source units, intercon' necting media between said units, said circuit and the ground, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said units to apply elcctromotive force at a fre quency suitable for signaling current ilowin said system, concurrently between one and the other of the ends of said circuit, and be tween the ground and said circuit ends.

11. In a signal system.-a signal circuit, a current supply source, supplemental current supply mechanism, interconnecting media between said source, said mechanism, said circuit and the ground, and continuously 'acting means for so varying the effectiveness of certain portions of said media as to cause said, source and said mechanism to apply electromotive force at a frequency suitable for signaling current'flow in said system, concurrently between one and the other of the ends of said circuit, and between the ground and said circuit ends.

12. Ina signal system,a signal circuit, current supply mechanism, interconnecting media between said mechanism, said circuit and the ground, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said mechanism to apply elci'ttromotive force of similar mean etl'ectiveness concurrentlv between one and the other of the ends of said circuit and between the ground and said circuit ends.

13. In a signal system r-a signal circuit. current supply mechanism, interconnecting media between said mechanism, said circuit and the ground. and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said mechanism to apply eleuromotire force at a frequency su' ble for signaling current tlow in said s :ein, concurrently between one and the other of the cans of said circuit and between the ground and said circuit ends.

14-. In a signal system comprising two line. conductors and a ground conductor,three current supply source units; interconnecting media between said units and said conductors, arranged to connect the terminals of one of said units to respective ones of two of said conductors; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said units to apply electromotiv forces of similar mean effectiveness concurrently between the Iii third of said conductors and one and the other of said two conductors.

15.111 a signal system comprising two line conductors and a ground conductor, a currentsupply source the terminals of which are connected to two of said conductors. supplemental current supply mechanism interconnecting media between said mechanism, said source and the third of said conductors, and continuously acting means for so varying the effectiveness oi certain portions of said media as to cause said source and said mechanism to apply electromotive forces of similar mean effectiveness concurrently between the third of said conductors and one and the other of said two conductors.

16. In a signal system comprising two line conductors and a ground conductor, three current supply source units the electro motive force of each of two of which suitably exceeds that of the third of said units; interconnecting media between said units and said conductors, arranged to connect the terminals of said third of said units to the respective ones of two of said conductors; and continuously actin means for so varying the effectiveness ot certain portions of said media as to alternately connect tile third of said conductors with one and the other of the terminals of said third unit through respective ones of the other two of said units.

17. In a signal system comprising two line conductors and a ground conduetor,a current supply source; supplemental current supply mechanism the electromotive force of which suitably exceeds that of said source; "iterconnecting media between said source. said mechanism and said conductors. arranged to connect the respective terminals of said source to two of said conductors; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force concurrently between one and the other of the terminals of said source and the third of said conductors at a frequency suitable for signaling current flow in said system.

18. In a signal system comprising two line conductors and a ground conductori thrce current supply source units; interconnecting media between said units and said conductors arranged to connect the terminals of one of said units to respective ones of two of said conductors; and continuously acting means for so va 'ying the effectiveness of certain portions of said media as to alternately connect the third of said conductors with one and the other of the terminals of said one of said units through respective ones of the other two of said units at a frequency suitable for signaling current flow in said system;

19. In a signal system comprising two line conductors and a ground conductor,

current supply source; supplemental current supply mechanism; interconnecting media between said source, said mechanism and said conductors arranged to connect the respective terminals of said source to two of said conductors; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force concurrently be tween one and the other of the terminals of said source and the third of said conductors at a frequency suitable for signaling current flow in said system.

20.111 asignal system comprising two line conductors and a ground conductor;- current supply mechanism. interconnecting media between said mechanism, and said conductors arranged to connect terminals of said mechanism to two of said conductors. and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said mechanism to apply electromotive force concurrently between one and the other of said two conductors and the third of said conductors at a frequency suitable for signaling current flow in said system.

21. In a signal system.--a signal circuit. a manifesting deviccomprising a controlling magnet having two windings. a current supply source connected between the respective ends of said circuit, two supplemental current supply sources, interconnecting media between said sources, said circuit and the ground, and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately ground one and the other of the terminals of said first named source through respective ones of said second named sources and through one and the other of said two windings in such manner that current flow in the intended direction through each of said. windings will cause like polarity of magnetization of saidmagnet at a frequency suitable for signaling current flow in said system.

22. In a signal system,'a signal circuit, a manifesting device comprising a control-- ling magnet having two windings, a current supply source, supplemental current supply mechanism interconnecting media between said windings, said source, said mechanism, said circuit and the ground, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force, at a frequency suitable for signaling current flow in said system, concurrently between one and the other ends of said circuit and, through one and the other of said two windings of such respective polarities that current flow in the intended direction through each of said windings will cause like polarity of magnetization of said magnet between the ground and said circuit ends.

23. In a signal system,--a signal circuit a manifesting device comprising a controlling magnet having two windings, current supply mechanism, interconnecting media between said windings, said mechanism, said circuit and the ground, and continuously acting means for so varying the effectiveness of certain portions of said media as tocause said mechanism to concurrently apply electromotive force at a frequency suitable for signaling current flow in said system between one and the other ends of said circuit and, through one and the other of said two windings of such respective p0 larities, that current flow in the intended direction through each of said windings will cause like polarity of magnetization of said magnet between the ground and said circuit ends.

24. In a signal system,-a signal circuit; a common return conductor associated therewith; three current supply source units the clec-tromotive force of each of two of which units suitably exceeds that of the third of said units; interconnecting media between said units, said circuit and said conductor, arranged to connect the terminals of the said third one of said units to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately connect sald conductor to one and the other of the terminals of said third of said units through respective ones of the other of said units at a frequency suitable for signaling current flow in said system.

25. In a signal systen1,a signal circuit; a common return conductor associated therewith; a current supply source; supplemental current supply mechanism' the electromotive force of which suitably exceeds that of said source; interconnecting media between said source, said mechanism, said circuit and said conductor, arranged to connect the terminals of said source to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force concurrently between one and the other ends of said circuit and said conductor at a frequency suitable for signaling current flow in said sys tem,

26. In a signal system,a signal circuit; a common return conductor associated therewith; three current supply source units; interconnecting media between saidunits, said circuit and said conductor, arranged to connect the terminals of one of said units to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said units to apply electromotive forces of similar mean effectiveness concurrently between said conductor and one and the other ends of said circuit. 7

27. In a signal system,-a signal circuit; a common return conductor associated therewith; a current supply source; supplemental current supply mechanism; interconnecting media between said source, said mechanism, said circuit and said conductor, arranged to connect the terminals of said source to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive forces of similar mean effectiveness concurrently between one and the other of the ends of said circuit, and between said conductor and said circuit ends.

28. In a signal system,a signal circuit; a common return conductor associated therewith; three current supply source units; interconnecting media between said units, said circuit and said conductor, arranged to con nect the terminals of one of said units to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately connect said conductor to one and the other of the terminals of said one of said units through respective ones of the other two of said units at a frequency suitable for signaling current flow in said system.

29. In a signal system,a signal circuit;

common return conductor associated therewith; a current supply source; supplemental current supply mechanism; interconnecting ine'lia between said source, said mechanism, said circuit and said conductor, arranged to connect the terminals of said source to the respective ends of said circuit; and continuously acting means for so varying the etlectiveness of certain portions of said media as to cause said source and said mechanism to apply electro-motive force concurrently between one and the other ends of said circii and said conductor at a -lrequency suitable for signaling current flow in said system.

30. In a signal system,a signal circuit; a common return conductor associated there with; current supply mechanism; intercon necting media between said mechanism, said circuit and said conductor, arranged to connect terminals of said mechanism to the respective ends of said circuit; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said mechanism to apply electromotive force concurrently between one and the other ends of said circuit and said conductor at a frequency suitable for signaling current flow in said system.

31. In a signal system,a signal circuit, a common return conductor associated therewith; three current supply source units, intcrconnecting media between said units, said circuit and said conductor, and continuously acting means for so varying the effectiveness of certain portions'of said media as to cause said units to apply electromotive forces of similar mean ellectiveness concurrently between one end and the other of the ends of said circuit and between said conductor and said circuit ends.

32. In a signal system,a signal circuit, a common return conductor associated therewith, a current supply source, supplemental current supply mechanism, interconnecting media between said source, said mechanism, said circuit and said conductor, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive forces or" similar mean e'lfectiven-ess concurrently between one and the other of the ends of said circuit and between said conductor and said circuit ends.

In a signal system,a signal circuit, a common return conductor associated therewith, three current supply source units, interconnecting media between said units, said circuit and said conductor, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said units to apply electromotive force at a frequency suitable for signaling current How in said system, concurrently between one and toe other of the ends of said circuit and between said conductor and said circuit ends.

in a signal system, a signal circuit, a common return conductor associated therewith, a current supply source, supplemental current supply mechanism, interconnetting media between said source, said mechanism, saiu circuit and said condutor, and continuously acting means for so varyinn the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force at a frequency suitable for signaling current flow in said system, concurrently between one and the other of the ends of said circuit, and between said (OIHlEClZOl and said circuit ends.

in a signal system,-a signal circuit, a c mmen return conductor associated therewith, current supply mechanism, interconnecting media between said mecnanisimsaid circuit and said conductor, and continuously acting means for so varying the eiiectiveness of certain p0 tions of said media as LO cause said mechanism to apply electromotive force 0t similar mean effectiveness concur rentl between one and the other of the ends of said circuit and between said conductor and said circuit ends.

36. in a signal system,a signal circuit, common r-et :rn conductor associated therewith, current supply mechanism, interconnecting media between said mechanism, said circuit and said conductor, and continuously acting means for so varying the etl'ectiveof certain portions of said media as to cause said mechanism to apply GlLCtlODlO- tive force at a frequency suitable for signaling current .ticw in said system, concurrently between one and the other of the ends of said ciruit and between said conductor and said circuit ends.

3'7. In a signal system comprising two line conductors and a common return conductor,three currelt supply source units; interconnecting media between said units and said conductors, arranged to connect the terminals of one of said units to respective ones of two of said conductors; and continuously acting means for so varying the effectiveness of certain portions ot' said media as to cause said units to apply electroinotive forces of similar mean (e fectiveness concurrently between the third of said con ductors and one and the other of said two conductors.

.38. In a signal system comprising two line conductors and a common return condu tor.-a current supply source the terminals of which are connected to two of said conductors, supplemental current supply mechanism, interconnecting media between said mechanism. said source and the third of said conductors, and continuously acting means for so varying the effectiveness of certain portions of saidmedia as to cause said source and said mechanism to apply electromotive forces of similar mean effectiveness concurrently between said third of said conductors and one and the other of said two conductors.

39. In a signal system comprising two line conductors and a common return conductor,tl1ree current supply source units the electromotive force of each of two of which suitably exceeds that of the third of said units; interconnecting media between said units and said conductors, arranged to connect the terminals of said third of said units to the respective ones of two of said conductors; and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately connect the third of said conductors with one and the other of the terminals of said third unit through respective ones of the other two of said units.

40. In a signal system comprising two line conductors and a common return con ductor,--a current supply source; supplemental current supply mechanism the electromotive force of which suitably exceeds that of said source; interconnecting media between said source, said mechanism and said conductors, arranged to connect the respective terminals of said source to two of said conductors; and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force concurrently between one and the other of the terminals of said source and the third of said conductors at a frequency suitable for signaling currentflow in said system.

41, In a signal system comprising two line conductors and acommon return conductor,three current supply source units; interconnecting media between said units and said conductors, arranged to connect the terminals of one of said units to respective ones of two of said conductors; and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately connect the third of said conductors with one and the other of the terminals of said one of said units through respective ones of the other two of said units at a frequency suitable for signaling current flow in said system.

42. In a signal system comprising two line conductors and a common return conductor,-a current supply source; supplemental current supply mechanism; interconnecting media between said source, said mechanism and said conductors, arranged to connect the respective terminals of said source to two of said conductors; and continuously acting means for so varying the effectiveness of certain portions" of said media as to cause said source and said mechanism to apply electromotive force concurrently between one and the other of the terminals of said source and the third of said conductors at a frequency suitable for signaling current flow in said system.

43. In a signal system comprising two line conductors and a common return conduc tor,current supply mechanism, interconnecting media between said mechanism and said conductors arranged to conn-ectterminals of said mechanism to two of said conductors, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said mechanism to apply electromotive force concurrently between one and the other of said two conductors and the third of said conduc tors at a frequency suitable for signaling current flow in said system.

44. In a signal system,a signal circuit, a common return conductor associated therewith, a. manifesting device comprising a controlling magnet having two windings a current supply source connected between the respective ends of said circuit, two supplemental current supply sources, interconnecting media between said sources, said circuit and said conductor, and continuously acting means for so varying the effectiveness of certain portions of said media as to alternately connect said conductor to one and the other of the terminals of said first named source through respective ones of said second named sources and through one and the other of said two windings in such manner that current flow in the intended direction through each of said windings will cause like polarity of magnetization of said magnet, at a frequency suitable for signaling current flow in said system. a

45. In a signal system,a signal circuit, a common return conductor associated therewith, a manifesting device comprising a controlling magnet having two windings, a

current supply source, supplemental current supply mechanism, interconnecting media between said windings, said source, said mechanism, said circuit and said conductor, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said source and said mechanism to apply electromotive force, at a frequency suitable for signaling current flow in said system, concurrently between one and the'other ends of said circuit and, through one and the other of said two windings of such respective polarities that current flow in the intended direction through each of said windings will cause like polarity of magnetization of said magnet. between said conductor and said circuit ends.

4-6. In a signal system,-a signal circuit, a

common return conductor associated therewith, a manifesting device comprising a-controlling magnet having two windings current supply mechanism, interconnecting media. between said windings, said mechanism,

said circuit and said conductor, and continuously acting means for so varying the effectiveness of certain portions of said media as to cause said mechanism to concurrently apply electromotive force at a frequency suitable for signaling current flow in said system between one and the other ends of said circuit and, through one and the other of said two windings of such respective polarities that current flow in the intended direction through each of said windings will cause like polarity of mag netization of said magnet, between said con ductor and said circuit ends.

47. In a signal system having a conductor to which electromotive forces of opposite polarity are alternately applied through respective ones of two current paths at a frequency suitable for signaling current How, a manifesting device comprising a controlling magnet having two windings, said windings so connected in said paths, respectively, that intended current flow through each of said windings will cause like polarity of magnetization of said magnet.

In witness whereof, I hereunto subscribe my name, this 3rd day 01 October, 1923.

C. E. BEACH. 

